CSLB C-8 Concrete (Trade Exam) — All Questions
The figures these questions turn on, laid out by section on dense colour pages you can print: CSLB C-8 Concrete cheat sheet PDF — $9.99 →
250 questions
For specified textures, what does the referenced specification require the contractor to build?
- a.A photograph that the owner approves
- b.A mock-up only after a complaint
- c.A lab sample sent to the inspector
- d.A test panel for each type of texture✓
The specification requires test panels for each type of specified texture so the finish can be approved before the work proceeds. Lab samples, complaint-driven mock-ups, and photographs do not show the actual finish.Caltrans Reinforced Concrete Construction Manual (June 2025), ch. 5
When is the most critical time of the curing period?
- a.Only after the forms come off
- b.When the cylinders are broken
- c.The last day of the period
- d.Immediately after placement✓
Caltrans says the most critical time is right after placement, when moisture loss does the most damage. The last day, post-stripping, and cylinder breaks come after the critical window.Caltrans Reinforced Concrete Construction Manual (June 2025), ch. 5
Cracks appear on a newly cast surface before curing compound has been applied. What does Caltrans advise?
- a.Broom the surface lightly to close the cracks up
- b.Wait for the bleed water to return to the surface
- c.Spray a double coat of compound over the cracks
- d.Apply atomized water at once until compound goes on✓
The contractor should apply atomized water at once and keep it up until curing compound is applied. Compound over a drying surface is not the fix, waiting lets more cracks form, and brooming does not close them.Caltrans Reinforced Concrete Construction Manual (June 2025), ch. 5
What is the purpose of a fugitive dye in a clear curing compound?
- a.To match the color of the slab permanently
- b.To show coverage with a fading red tint✓
- c.To make the compound dry out much faster than usual
- d.To harden the top layer of the concrete surface
A fugitive dye tints the compound red while it is applied so coverage can be seen, and fades as it dries. It does not change drying speed, harden the surface, or leave a lasting color.Caltrans Reinforced Concrete Construction Manual (June 2025), ch. 5
If curing compound is left in place, what does it do between successive layers of concrete?
- a.It greatly improves the bond
- b.It fills the surface voids
- c.It speeds up the initial set
- d.It acts as a bond breaker✓
Left in place, curing compound acts as a bond breaker, which is why it is removed before the next pour. It does not improve bond, fill voids, or accelerate set.Caltrans Reinforced Concrete Construction Manual (June 2025), ch. 5
Which four factors determine the rate of evaporation from fresh concrete?
- a.Slump, cement type, aggregate size and slab thickness
- b.Form material, bar spacing, truck speed and crew size
- c.Concrete temperature, air temperature, wind velocity and humidity✓
- d.Water-cement ratio, air content, sand fineness and the admixture type used
Evaporation depends on concrete temperature, air temperature, wind velocity and humidity, which together drive plastic shrinkage cracking. Mix properties, form and steel details, and truck or crew factors do not set the evaporation rate.Caltrans Reinforced Concrete Construction Manual (June 2025), ch. 5
What must be done to strength-test cylinders after they are made?
- a.Strip the molds and weigh them within the hour
- b.Protect them from evaporation✓
- c.Leave them uncovered so they can air-dry
- d.Warm them up to speed their strength gain
Precautions must be taken to prevent evaporation and water loss from the specimens. Air drying and heating change the result, and stripping within the hour would damage fresh specimens.UFGS 03 30 00 Cast-in-Place Concrete (Chg 10, Aug 2025)
Which ASTM test method does the federal guide specification cite for slump?
- a.ASTM C39
- b.ASTM C172
- c.ASTM C231
- d.ASTM C143✓
Slump tests follow ASTM C143. C172 covers sampling fresh concrete, C39 is the compressive strength test for cylinders, and C231 is the pressure method for air content.UFGS 03 30 00 Cast-in-Place Concrete (Chg 10, Aug 2025)
Which ASTM method does the federal guide specification cite for the maturity method of assessing in-place strength?
- a.ASTM C873
- b.ASTM C138
- c.ASTM C1074✓
- d.ASTM C1107
The maturity method is ASTM C1074. C873 is the test for cast-in-place cylinders, C138 measures unit weight, yield and gravimetric air content, and C1107 is the nonshrink grout standard.UFGS 03 30 00 Cast-in-Place Concrete (Chg 10, Aug 2025)
What does a penetrating sealer do for fine cracks and pores in concrete?
- a.It fills and bridges cracks up to 1/4 inch wide
- b.It dissolves salts and carries them out of the slab
- c.It repels water without bridging cracks✓
- d.It seals them beneath a hard, glossy surface film
Penetrating sealers make fine cracks and pores water-repellent (hydrophobic) but do not bridge or fill cracks. They do not fill cracks, they are not film-forming, and they do not remove salts.National Park Service Preservation Brief 15
Want these explained in order? CSLB C-8 Concrete Trade Exam Study Guide (2026) — PDF + EPUB, $24.99 · 14-day refund →
What must a Caltrans contractor submit before staining concrete?
- a.A tint order signed by the paint supplier
- b.Cylinder results from the 28-day breaks
- c.A written weather forecast for the whole week
- d.A staining plan and stain test panels✓
The contractor submits a staining work plan and test panels for staff review and authorization before staining. A tint order, cylinder results, and a forecast do not show how the stain will look.Caltrans Reinforced Concrete Construction Manual (June 2025), ch. 5
Where do the surface-preparation requirements for staining concrete come from?
- a.Whatever the foreman's usual practice has been on past jobs
- b.Manufacturer instructions and contract specifications✓
- c.The ready-mix supplier's delivery ticket notes
- d.The weather service's forecast for the week
Surface preparation follows the manufacturer's instructions and the contract specifications. A foreman's habit, a delivery ticket, and a weather report are not the source of those requirements.Caltrans Reinforced Concrete Construction Manual (June 2025), ch. 5
Before a full-scale cleaning of concrete begins, what does NPS guidance call for?
- a.Trial samples of the cleaning process✓
- b.A fresh coat of curing compound
- c.Strong muriatic acid on a small corner
- d.A pressure wash of the whole wall
For any cleaning process, trial samples should be done before full-scale work. A full wash skips the test, strong acids such as muriatic acid should not be used on concrete, and curing compound has nothing to do with cleaning.National Park Service Preservation Brief 15
Under the federal guide specification, what must happen before materials that adsorb VOCs are installed over a sealed slab?
- a.Wash the slab down with clean water
- b.Let the compound or sealer cure first✓
- c.Apply a second coat of compound first
- d.Cover the surface with plastic sheeting
Curing compound or sealer installations must cure before materials that adsorb VOCs go in. A second coat, plastic cover, and washing do not address the off-gassing.UFGS 03 30 00 Cast-in-Place Concrete (Chg 10, Aug 2025)
What mortar proportion does Caltrans cite from its contract specification for the dry-pack mortar used in a simple patch?
- a.1 part cement to 3 parts sand
- b.1 part cement to 2 parts sand✓
- c.1 part cement to 4 parts sand
- d.1 part cement to 1 part sand
The mortar is made by mixing 1 part cement with 2 parts sand and only enough water to moisten it. 1:1 is richer than specified, and 1:3 and 1:4 are leaner.Caltrans Reinforced Concrete Construction Manual (June 2025), ch. 5
In the simple dry-pack patch procedure, how is the finished mortar patch cured?
- a.With the water method for 12 hours
- b.With the water method for 72 hours✓
- c.With curing compound for 3 hours only
- d.Left dry for 72 hours
The patch is cured with the water method for 72 hours. Leaving it dry skips curing, 12 hours and 3 hours are too short.Caltrans Reinforced Concrete Construction Manual (June 2025), ch. 5
Which ASTM standard does the federal guide specification cite for nonshrink grout?
- a.ASTM C143
- b.ASTM C172
- c.ASTM C1107✓
- d.ASTM C1074
Nonshrink grout is specified under ASTM C1107. C1074 is the maturity method, C143 is slump, and C172 is sampling fresh concrete.UFGS 03 30 00 Cast-in-Place Concrete (Chg 10, Aug 2025)
When a groove is filled with joint sealing compound, how full should it be?
- a.Slightly underfilled, so it cannot squeeze out✓
- b.Filled with sand and topped off with a layer of grout
- c.Left empty until the compound skins over
- d.Overfilled to leave a raised bead on top
The groove is slightly underfilled so the compound cannot squeeze out as the joint moves. A raised bead would be pushed out, sand and grout make a rigid plug, and an empty groove is not sealed.UFGS 03 30 00 Cast-in-Place Concrete (Chg 10, Aug 2025)
Right after forms come off, how can suspect locations be checked for voids?
- a.Weigh each suspect section on a hand-held scale
- b.Tap with a hammer or drag a chain over them✓
- c.Spray them with water and look for small bubbles
- d.Compare the surface color against a paint chip
Tapping with a light hammer or dragging a chain gives a dull or hollow sound over voids. Water bubbles, weighing a section, and color comparison do not find voids behind the surface.Caltrans Reinforced Concrete Construction Manual (June 2025), ch. 5
Under Title 8 §1510, who may operate equipment and machinery on a construction job?
- a.Any employee over 18
- b.Only qualified persons✓
- c.The most senior worker on the crew
- d.Anyone who has watched it used
The employer permits only qualified persons to operate equipment and machinery. Age, having watched, and seniority are not the test of being qualified.Cal. Code Regs. tit. 8, §1510
What must be true of personal protective equipment selected for employees?
- a.It must come in one standard crew size
- b.It must be purchased by each employee
- c.It must be bright orange or lime green
- d.It must fit each affected employee✓
PPE is selected to ensure it properly fits each affected employee and is used per the manufacturer's instructions. One-size PPE fits poorly, the employer supplies required PPE, and color is not the fit requirement.Cal. Code Regs. tit. 8, §1514
When must employees wear approved head protection under Title 8 §3381?
- a.When working more than 6 feet above the ground or grade level
- b.When flying or falling objects, or shock and burns, are a risk✓
- c.When working directly below a crane, hoist or boom
- d.On public works projects, highways and bridge jobs
Head protection is required wherever flying or falling objects, or electric shock and burns, could injure the head. Crane work, a height threshold, and public jobs are narrower than the rule.Cal. Code Regs. tit. 8, §3381
Which exposure calls for foot protection under Title 8 §3385?
- a.Work that is carried out in wet or muddy weather
- b.Falling objects, crushing or penetration✓
- c.Work done in cold weather or on frozen ground
- d.Concrete dust blowing across the slab
Foot protection is required where employees face falling objects, crushing or penetrating actions, electrical hazards, or hot or corrosive substances. Cold ground, wet weather and blowing dust are not the listed hazards.Cal. Code Regs. tit. 8, §3385
What does Title 8 say about loose sleeves, ties and cuffs around machinery?
- a.They are fine, provided they are tucked into gloves
- b.They must not be worn where they could get entangled✓
- c.They are fine for concrete finishers on the slab
- d.They are fine whenever the machine has a guard on it
Loose clothing must not be worn around machinery in which it might become entangled. Tucking, trade exceptions, and guards do not remove the entanglement hazard.Cal. Code Regs. tit. 8, §1522
A finisher's boot fills with wet concrete, and the worker keeps working. What injury can result?
- a.Frostbite from the cooling of the evaporating water
- b.A lung disease from breathing in silica dust
- c.Chemical burns or ulcers from trapped concrete✓
- d.Only a minor drying of the skin that fades by evening
Wet concrete trapped against skin, as when it falls inside boots, can cause first, second or third degree burns or ulcers. Drying alone understates it, frostbite is not the mechanism, and silicosis comes from inhaled dust.CPWR/eLCOSH, Cement Hazards and Controls
A worker wants to wash cement off his hands in a bucket used to clean tools. What does the guidance say?
- a.Fine, as long as the bucket water is kept warm
- b.Fine, if the bucket is refilled with water every hour
- c.No; rinse with clean water only✓
- d.Fine, because any water at all will dilute the cement
Hands should not be washed in water from buckets used for cleaning tools, since that water carries cement. Dilution, warm water, and an hourly refill do not make it clean.CPWR/eLCOSH, Cement Hazards and Controls
Table 1 of the silica standard lists a work practice for cleaning holes drilled in concrete. What is it?
- a.Wipe them with a dry rag
- b.Use a HEPA-filtered vacuum✓
- c.Blow them out with compressed air
- d.Sweep them dry with a stiff broom
The Table 1 practice is a HEPA-filtered vacuum, which captures respirable dust. Compressed air, dry sweeping and dry wiping all put silica back into the air.Cal. Code Regs. tit. 8, §1532.3
Which engineering control does Table 1 of the silica standard list for a handheld powered chipping tool?
- a.Dry chipping, with the worker standing upwind
- b.Continuous water spray at the point of impact✓
- c.A damp rag laid over the tool to catch the dust
- d.A large fan blowing the dust away from the worker
Table 1 lists a water delivery system that supplies a continuous stream or spray of water at the point of impact. A fan, an upwind stance, and a rag are not listed controls.Cal. Code Regs. tit. 8, §1532.3
Noise exposure still exceeds Table N-1 after feasible controls. What does Title 8 say about ear protection?
- a.The employer supplies it and requires it✓
- b.It is issued when a worker asks for it
- c.Workers must buy their own at the supply store
- d.It is required once levels pass 105 dBA
Ear protection is provided by the employer, who must require employees to wear it. Employee purchase, issue on request, and a 105 dBA threshold are not what the rule says.Cal. Code Regs. tit. 8, §1521
A finisher on a hot day is staggering, vomiting and disoriented. What does §3395 require of the employer?
- a.Implement emergency response procedures✓
- b.Offer water and wait 30 minutes
- c.Send the worker home to rest
- d.Move the worker to a shaded area for the shift
Signs such as decreased consciousness, staggering, vomiting, disorientation or convulsions indicate severe heat illness and call for emergency response procedures. Sending someone home alone, waiting, and shade alone are not enough.Cal. Code Regs. tit. 8, §3395
A worker shows signs of heat illness. May the employer simply send the worker home alone?
- a.Yes, when the shift is nearly over anyway
- b.No; monitor the worker and offer first aid✓
- c.Yes, if a coworker can give the worker a ride
- d.Yes, as long as the worker agrees to go home
A worker with heat illness symptoms must be monitored and not left alone or sent home without being offered first aid or emergency medical services. Consent, shift length, and a ride do not satisfy the rule.Cal. Code Regs. tit. 8, §3395
Where a person's eyes or body could be exposed to corrosive materials, what must be readily accessible?
- a.Drenching or eye-flushing facilities✓
- b.A first-aid manual kept in the site office trailer
- c.A case of bottled drinking water kept in the truck
- d.An eyewash station at the contractor's main yard
Title 8 requires conspicuous, readily accessible drenching or flushing facilities with clean water. Drinking water, a manual, or a distant eyewash will not give the fast flushing that corrosive exposure needs.Cal. Code Regs. tit. 8, §1512
What does Title 8 §5194 require employers to give employees about the hazardous chemicals they may be exposed to?
- a.A hazard communication program with labels and SDSs✓
- b.One verbal warning given at the time of hiring
- c.A laminated first-aid card for each chemical that is used
- d.Chemical information only after an injury occurs
Employers must provide this information through a hazard communication program, labels and other warnings, and safety data sheets, with training. A single warning, a first-aid card, and after-injury disclosure fall short.Cal. Code Regs. tit. 8, §5194
What does a respirator fit test do?
- a.It rates how efficient the filter cartridge is at stopping dust
- b.It records the medical clearance of the worker
- c.It checks how well a respirator fits one person✓
- d.It measures the lung capacity of the worker
A fit test uses a protocol to qualitatively or quantitatively evaluate the fit of a respirator on an individual. Lung capacity, filter ratings, and medical clearance are different parts of a respiratory program.Cal. Code Regs. tit. 8, §5144
May waste, materials or tools be thrown from a structure to where employees may be below?
- a.Yes, provided a worker calls out a warning first
- b.Yes, provided each piece weighs less than 5 pounds
- c.Yes, provided the drop is under 10 feet in height
- d.Not unless the fall zone is guarded or barricaded✓
Throwing is prohibited toward areas where employees may be unless the fall area is guarded. A shouted warning, a weight limit, and a height limit are not exceptions.Cal. Code Regs. tit. 8, §1513
Scaffolds are required for work that cannot be done safely from permanent or solid construction at least how wide?
- a.12 inches
- b.20 inches✓
- c.36 inches
- d.24 inches
Title 8 requires scaffolds for work that cannot be done safely from permanent or solid construction at least 20 inches wide, unless it can be done from ladders. 12 inches is too narrow, and 24 and 36 inches are not the stated width.Cal. Code Regs. tit. 8, §1637
Which kind of ladder may not be used on a construction job under Title 8?
- a.Double-cleat job-made ladders
- b.Single-rail ladders✓
- c.Single-cleat job-made ladders
- d.Metal ladders with non-slip feet
Single-rail ladders are not permitted. Single-cleat and double-cleat job-made ladders are allowed within their length limits, and non-slip feet are a normal feature.Cal. Code Regs. tit. 8, §1675
What size and spacing do Title 8 railings require for wood posts?
- a.At least 4 by 4 inches, spaced up to 16 feet apart on center
- b.At least 2 by 4 inches, spaced 8 feet apart or closer✓
- c.At least 2 by 4 inches, spaced up to 12 feet apart
- d.At least 1 by 4 inches, spaced up to 10 feet apart
Wood posts must be not less than 2 inches by 4 inches, spaced at 8-foot or closer intervals. A 1-by-4 is too small, and the 10-, 12-, and 16-foot spacings are too wide.Cal. Code Regs. tit. 8, §1620
A worker at grade will work beside exposed, protruding rebar. Up to what height above grade must the exposed ends be guarded against impalement?
- a.4 feet
- b.2 feet
- c.10 feet
- d.6 feet✓
Exposed ends extending up to 6 feet above grade or the work surface must be guarded with covers or troughs. 2 and 4 feet leave tall ends unguarded, and 10 feet is not the stated limit.Cal. Code Regs. tit. 8, §1712
Job-built troughs may substitute for engineered protective covers only when workers are at heights of no more than what?
- a.3 feet above grade or the working surface
- b.12 feet above grade or the working surface
- c.7 1/2 feet above grade or the working surface
- d.6 feet above grade or the working surface✓
The trough substitute is limited to heights not greater than 6 feet. 3 feet is lower than needed, 7 1/2 feet is the fall-exposure limit for protective covers generally, and 12 feet is not stated.Cal. Code Regs. tit. 8, §1712
Who must inspect concrete pump hoses, clamps and pipes before use?
- a.A qualified attendant or operator✓
- b.The finishing foreman, once the pour has finished
- c.The ready-mix truck driver, checking once each week
- d.No one at all, as long as the equipment is new
Hoses, clamps and pipes are inspected before use by a qualified attendant or operator, and damaged items must not be used. A weekly driver check, a post-pour check, and skipping inspection for new gear do not meet the rule.Cal. Code Regs. tit. 8, §1720
A concrete bucket has a hydraulic or pneumatic gate. What does Title 8 require?
- a.A device to prevent accidental dumping✓
- b.A load meter on the crane hoist line
- c.A second gate that is held shut with a pin
- d.A flashing warning light on the bucket
Buckets with hydraulic or pneumatic operating gates need devices that prevent accidental dumping. A pinned second gate, a load meter, and a light do not prevent a release.Cal. Code Regs. tit. 8, §1720
What does Title 8 say about the handles of concrete buggies?
- a.They may not stick out past either wheel✓
- b.They must be at least 6 feet long overall
- c.They must be covered in padded rubber
- d.They must extend past the wheels for leverage
Buggy handles shall not extend beyond the wheels on either side, so they cannot catch on forms or workers. Longer handles, a length minimum, and padding are not what the rule requires.Cal. Code Regs. tit. 8, §1720
May tools, materials or equipment be handled over live overhead high-voltage lines?
- a.Yes, as long as the wires look like they are fully insulated
- b.Yes, as long as it is kept 3 feet above the lines
- c.No, unless the lines are de-energized and visibly grounded✓
- d.Yes, as long as the operator holds a certification
Operation over energized high-voltage lines is prohibited, with the exception of lines that are de-energized and visibly grounded. A small clearance, an operator certification, or insulated appearance do not allow it.Cal. Code Regs. tit. 8, §2946
A ready-mix truck is parked on an incline. What does Title 8 require for equipment parked there?
- a.The parking brake, set firmly on the truck
- b.A warning sign placed at the rear bumper
- c.The front wheels turned toward the curb
- d.Wheels chocked and the parking brake set✓
Equipment parked on inclines needs wheels chocked and the parking brake set, or equally effective mechanical means. A brake alone, a sign, and wheel position do not stop a rolling vehicle if the brake fails.Cal. Code Regs. tit. 8, §1593
What training must flaggers have under Title 8 §1599?
- a.Training in proper flagging before they are assigned✓
- b.No training, as long as they wear a high-visibility vest
- c.A current CPR card instead of a flagging course
- d.A short orientation given after their first shift
Flaggers must be trained in the proper fundamentals of flagging before being assigned. A vest alone, after-the-fact orientation, and a CPR card do not teach flagging.Cal. Code Regs. tit. 8, §1599
While formwork and shoring are being erected, when must the first protective guardrails go in at the perimeter?
- a.Once the first full week of erection is done
- b.After the deck concrete is placed and has set
- c.Right after the supports are in place✓
- d.After the forms have been stripped for reuse
The first set of protective guardrails is installed at the perimeter right after the supporting members are in place. Waiting for concrete, stripping, or a week leaves workers exposed during erection.Cal. Code Regs. tit. 8, §1717
Who may work below a building floor form installation?
- a.Only people installing, removing or inspecting it✓
- b.Any trade at all, once the normal workday has ended
- c.Any worker on the job who is wearing a hard hat
- d.Finishers who are waiting around for the pour
Employees are prohibited from working below a floor form installation except those actually engaged in its installation, removal or inspection. A hard hat, off-hours, and waiting finishers are not exceptions.Cal. Code Regs. tit. 8, §1717
Lifting inserts embedded in tilt-up concrete members must support at least what multiple of the maximum intended load?
- a.One and a half times
- b.Three times
- c.Two times✓
- d.Five times
Lifting inserts must be capable of supporting at least two times the maximum intended load. One and a half is below the requirement, three times is not stated, and five times is the multiple for lifting hardware.Cal. Code Regs. tit. 8, §1715
Under Title 8 §1715, how long must tilt-up wall panels be supported against overturning and collapse?
- a.Until the slab concrete has cured seven days
- b.Until the permanent connections are completed✓
- c.Until the joints between panels are caulked
- d.Until the next panel in line is set
Tilt-up panels must be supported until permanent connections are completed as specified in the erection plan. Setting the next panel, caulking joints, and a seven-day slab cure do not make a panel stable by themselves.Cal. Code Regs. tit. 8, §1715